By giving it this title, the author is letting us know that the story is about Raymond. In a way, Squeaky runs the race for him and changes the way she looks at running. Squeaky (whose real name is Hazel) is the narrator. Raymond is her older brother, but he is slow. Much of Squeaky's time is spent protecting him. This includes making sure other kids don't tease him. Sometimes Raymond can be embarrassing. During the race, Squeaky watches him run and realizes that it's ok to be different.
Squeaky is a good runner, and she wants to win the May Day race more than anything. When she first starts, she just wants to beat everyone else and particularly Gretchen. Yet when she runs, she notices Raymond running on the other side of the fence. In an intense moment of introspection during the race, Squeaky realizes that running is something Raymond might be able to do, even though he cannot do everything a regular boy can.
And I’m smiling to beat the band cause if I’ve lost this race, or if me and Gretchen tied, or even if I’ve won, I can always retire as a runner and begin a whole new career as a coach with Raymond as my champion.
Squeaky is happy because she sees her brother differently, and she realizes that there is something in which they can understand each other, and an area where they can be equals.